Meter



E. W. NILES March 4, 1930.

METER Filed Dec. 14, 1927 a .miii

INVENTOR.

I ATTORNEY Patented Mar. 4, 1930 UNITED STATES PATENT OFFICE ELIOT W.NILES, OF BLOOMFIELD, NEKV JERSEY, ASSIGNOR TO AMERICAN TELEPHONE ANDTELEGRAPH COMPANY, A CORPORATION OF NEW YORK METER Application filedDecember 14, 1927. Serial No. 239,934.

This invention relates to measuring devices, and more particularly totelephone meters by means of which a subscriber is charged for thelength of time his telephone is in actual use.

In telephone metering systems, it has been proposed to operate the meterperiodically by varying the current or reversing the direction of theflow of the current in the telephone circuit. The present invention isadapted to be used in connection with such systems.

In the moving coil armature type of meter, a device has been suggestedin which the armature is mounted in a vertical position and vibrates ina manner'similar to that of an inverted pendulum. The armature, due toits mass, is acted upon by the force of gravity and tends to remain inor restore to either extreme position in its arc of vibration when thecoil is deenergized.

The present invention consists of a stationary permanent magnet havingconcentric pole pieces, a movable coil surrounding the inner pole pieceof said magnet and fastened to one end of an armature, spring reedssupporting said armature at the other end thereof, and compressiontoggle springs positioned along two opposite sides of said armaturebetween suitable supports. The force exerted by the compression springstends to cause the armature to remain in or restore to either extremeposition. The moving parts may be made so light that the eifect of theforce of gravity acting thereon is relatively negligible when the deviceis mounted in any position.

It is essential in the moving coil type of meter that when the telephoneis in actual use, the meter be as sensitive as possible to the smallline current, and that when the telephone conversation ceases, thearmature re main in or restore to either extreme position rather thanthe mid-position of its arc of vibration. If the armature does notrestore to either extreme position, false registration mid-position andeither extreme position without, at the same time, rendering the deviceinoperative to the small line current. It is also essential that thisrestoring force be as constant as possible during the travel of thearmature from either extreme position to its mid-position, or viceversa.

The resultant restoring force exerted on the armature of the meterhitherto employed was dependent primarily upon the force of gravity. Asthe armature moved along its path of travel from either extreme positionto its mid-position, the force tending to restore the armature to itsextreme position decreased very rapidly.

The resultant restoring force exerted on the armature of the meterconstituting the present invention is dependent primarily upon the forceexerted by the toggle springs. These springs are under greatestcompression when the armature is at its mid-position, and under leastcompression when the armature is at either extreme position. However, atthe same time the leverage force exerted by these springs is least whenthe armature is at its mid-position and greatest when the armature is ateither extreme position. The result is that as the armature moves alongits path of travel from either extreme position to its midposition, theresultant restoring force decreases very slowly because of the buildingup of the spring compression force which tends to counteract thereduction of the leverage force. Therefore, with equal restoring forceexerted on the armature at their extreme positions, the restoring forceexerted on the armature of the present invention at any given point onits arc of vibration between its midposition and either extremeposition, is greater than that exerted on the armature of the meterhitherto employed at the corresponding point on its arc of vibration.

It is the object of this invention to provide a meter which is positivein its operation, which reduces the danger of false registration to aminimum, which may be mounted in any position with equally efiicientresults, and which is inexpensive in initial cost and subsequentmaintenance.

Figure 1 of the drawing is a perspective view of the meter; Fig. 2 is aside View broken away when the movlng coil armature is in one of itsextreme positions, the indicator not being shown; and Fig. 3 is the sameview when the moving coil armature is in the other of its extremepositions. Correspondin elements are indicated by the same numera l s.

In the drawing, specifically Fig. 1, the stationary permanent magnet 1has adjacent or concentric pole pieces, 2 being the inner pole piece and3 being the outer. A number 22, preferably made of brass or othersimilar material, separates the outer pole piece from one end of theinner pole piece. The movable armature coil 4 is secured to a coil-arm 5which is supported by sprin reeds 6 and 6'. The spring reeds arefastened to the coil-arm and the plate support 7, which is preferablymade of brass or other similar material, by the clamps 8 and 8'. Thecompression toggle springs 9 and 9 are positioned along two sides of thearmature arm 5 and are held in place at one end by the supports 10 and10, which are fastened to the armature arm. At the other end the togglesprings are held in place by the threaded members 21 and 21', which arescrewed through the correspondingly threaded supports 11 and 11, whichin turn are fastened to the plate support 7. The supports 11 and 11' arepositioned above the pivotal center of the spring reeds 6 and 6'. It isobvious that supports 11 and 11' may be positioned below the pivotalcenter of the spring reeds and suitable means provided for fastening thesprings 9 and 9' to the members 21 and 21, in which case the springswould be extended rather than compressed as the armature moves along itspath of travel from either extreme position to its mid-position.However, by using compression s rings supported above the pivotal center0 the spring reeds or other pivotal elements, none of the components ofthe force exerted on the armature is exerted in a direction toward thepivotal elements. Thus, the pressure on the delicate pivotal elementswith consequent high friction loss and dama e thereto is reduced to aminimum. The orce exerted on the armature by the compression springsconstitutes a restoring force tending to cause the armature to remain inor restore to either extreme position of its arc of vibration. When thecoil is energized by the line current, the force causing the coil tomove in the magnetic field between the concentric pole pieces is greaterthan the force exerted on the armature by the compression springs. Whenthe coil is deenergized, the force causing the coil to move in themagnetic field between the concentric pole pieces is removed, and theforce exerted on the armature by the compression springs immediatelybecomes sufliciently positive to cause the armature to remain in orrestore to either extreme position. The compression on the togglesprings and hence the force tending to cause the armature to remain inor restore to either extreme position may be increased or decreased byadjusting the threaded members 21 and 21. The fact that when the coil isdeenergized, the armature always remains in or restores to eitherextreme position, prevents false operation of the meter when the currentis interrupted, as when the subscriber attempts to recall the operatorby flashing, during dialing, or at the termination of the call, whichwould occur if the armature restored to its mid-position when thecurrent is interrupted. The use of springreeds avoids the necessity ofemploying delicate bearings which are subject to damage due to handlingand which may become unreliable in operation due to corrosion and dirt.Also, the force exerted on the armature by the compression togglesprings in conjunction with the force due to the large radius ofgyration provides sufficient sluggishness of action wit light movingparts to prevent response to lar e forces of short duration, forexample, mec hanical vibration of the meter or the current used forringing signals. Additional sluggishness of action with li ht movingparts is obtained by the use of e dy current damping b means of a copperslug 12 inside the coil w ich is acted upon by the field of thepermanent magnet. nuts 13 and 13 are provided to serve as stops when thearmature reaches its extreme positions. These stops are made adjustablein order that the arc of vibration of the armature may be regulated.

In the particular embodiment shown, there are two spring reeds which areinsulated from the armature support and the armature, and

A bolt and a serve as conductors, for example, from the terminal wire 14to the wire 15 and the winding of the coil 4, and thence back throughthe wire 15 to the other terminal wire 14. The use of the supportingreeds as electrical conductors avoids the necessity of employingadditional current conducting means with consequent maintenancediificulties and drag on the armature.

There is connected to the armature a pawl 16 which operates aratchet-wheel 17. The rotation of the ratchet-wheel in turn op erates,by means of the connecting rod 18, an indicator 20. A holding pawl 19 isprovided to hold the ratchet-wheel in its rotated position. Thisinvention is not limited to the specific arrangement of the registeringmeans disclosed. Different arrangements may be employed when the meteris mounted in other positive to insure the armatures remaining in orrestoring to either extreme position when the coil is deenergized. Also,the 1 aving parts may be made so light that the rorc of gravity actingthereon will be relati l negligible and the meter may be mounh L"- anyposition with equal efficiency of operation. The fact that the devicemay be mounted in any position eliminates ger of false registration dueto the cree i of the meter on its supports out of position, which iscaused by vibration of the supporting structure.

The meter is designed so that the arnr tare will be ineither one of itsextreme po at all times when the subscribers teleph is not in use. Theoperation of the do. is as follows: At the beginning the con-- versationthe direction. of the flow of current is, for example, through theterminal w 'e 14, the spring reed 6, the wire 15, the windr 7' of thecoil 4, the wire 15, the spring reed '6' and the other terminal wire il. The coil is energized in such a Way, for example, that the coil ismoved away from the position shown in Fig. 2 through the field createdbetwe n the pole pieces. This movement of the c through the fieldcreated between the pieces moves the coil arm 5 to its other e tremeposition, as shown in Fig. 8. movement, by means of the pawl it), theratchet-wheel 17, which in turn, b of the shaft 18, operates the l'fiLlCWhen the direction of the flow of the curr is reversed, the currentflows through ti terminal wire let, the spring reed S, the w 15, thewinding of the coil 4, and thence back through the wire 15, the springreed 6, and the other terminal wire l l. With this d rection of thecurrent the coil moves away from the position shown in Fig. 3 throu hthe magnetic field between the two po e pieces. This movement of thecoil thr the field between the two pole pieces moms the armature arm 5back into the other c2;- treme position, as shown in Fig. 2. Thismovement again places the pawl 17 in tion to rotate the ratchet-wheelwhen tl I rent is reversed again. During the first lli' 'f of themovement of the armature thro arc, the force exerted by tle comp springs9 and 9 is opposing the more by the fact tl but this is counteractedforce causing the coil to move in netic field between the concentricpole and that exerted by the spring reeds 6 is greater than the forceexerted by the co "1- pression springs. During the latter h the travelthe force exerted by the co sion springs is assisting the movemen v thatexerted by the spring reeds is oppo I it. When. the coil is deenergined,t e force causing the coil to move in the iield between the concentricpole pieces is removed, and the force exerted by the compression springsimmediately becomes sulhciently positive to cause the armature to remainin or restore to either extreme position.

This invention may be used in connection with systems in which thecurrent is suddenreversed in which the ou ally reversed. Also, by providor by suitable adjustment of e that the coil arm will be restores a t eation to the position illustrated l ns invention may be used inconnection systems using pulsating currents to operate the meter. Undercertain conditions it may be desirable to the meter by spring that thearmature will tend to restore to :1 remain in the position to which itis oper ated by the normal. line battery pol :n'i y Furthermore, the useof the meter described is not limited to systems in which the subscriberis charged for the length of time his telephone is in use, but may beemployed in systems wher tie charge is made on a message basis.

It is to be understood that this invention, although disclosed in aparticular embodiment herein set forth, is capable of being enibodied inother forms without departing from the spirit of the invention or thescope of the appended claims.

What is claimed is:

1. In combination, a magnet having adjacent pole pieces, an armaturesupported by pivotal means, a. coil fastened to said armature andadapted to move between said pole pieces, and means under stressfastened to said armature and adapted to influence its movement throughits arc of Vibration.

2. In combination, a magnet having adjacent pole pieces, an armaturesupported by pivotal means, a coil fastened to said armature and adaptedto move bet-ween said pole pieces, and means under stress causing saidarmature to remain only in either extreme position of its path ofvibration when said coil is deenergized.

3. In combination, a magnet having concentric pole pieces, a coiladapted to move between said pole pieces, an armature fastened to saidcoil and adapted to be moved thereby, resilient means supporting saidarmature, and means under stress tending to counteract the force exertedon said armature by said resilient means and by said coil during part ofits movement through its arc of vibration when said coil is energized.

i. In combination, a permanent magnet one pole piece of which surroundsthe other, a coil adapted to move between said pole pieces, an armaturefastened to said coil and adapted to be moved thereby, resilient meansfastened to and supporting said armature, and compression springssecured at one end to said armature and at the other end to supportingmeans, said compression springs being adapted to cause said armature toremain only in either extreme position of its are of vibration when saidcoil is deenergized.

5. In combination a permanent magnet one pole piece of which surroundsthe other, 5 a coil adapted to move between said pole pieces, anarmature fastened to said coil and adapted to be moved thereby, springreeds fastened to and supporting said armature, said spring reeds beinginsulated from one another and electrically connecting terminal wireswith said coil, and compression springs secured at one end to saidarmature and at the other end to supporting means, said compressionsprings being adapted to cause said armature to remain only in eitherextreme position of its arc of vibration when said coil is deenergized.

In testimony whereof. I have signed my name to this specification this12th day of December, 1927.

ELIOT W. NILES.

